In the non-inflated state, airbags must be as small as possible and accommodated securely within the interior equipment of the vehicle, for example in dashboards, impact absorbers or side trim panels as well as in vehicle seats.
Today's vehicles are often equipped with lateral impact airbags, which may have the form of a lateral air curtain situated in a vehicle roof; or, alternatively or additionally, an airbag may be situated within a vehicle seat system.
One disadvantage of airbags that are located within a seat system is that the airbags must break through the seat material before they are able to inflate completely so as to protect a vehicle occupant. During the inflation, such an airbag may strike foam or other seat cushion materials and must then break through the seat cover in order to be able to exit the seat system. Here there is a problem of preventing the lateral region from being “shot through” in an uncontrolled manner and of avoiding the creation of individual foam particles when firing the airbag in order to protect the occupants.
A disadvantage is the fact that the hard cover structure of the airbag module that is used in most cases forms externally visible elevated upholstery regions after the vehicle seat has been “broken in” because of minimal changes in the foam part, for example in an open foam region developed laterally in the back rest.
Aside from the so-called hard cover airbag modules, however, so-called soft cover airbag modules are known as well.
The installation in the specified installation spaces is difficult because the task is one of accommodating an airbag that is folded only loosely, while at the same time ensuring a secure inflation. Since the folding of an airbag is important with regard to the type and reliability as well as the speed of inflation, the folded airbag is held by retaining straps or a so-called soft cover in the folded position during transport and installation until inflation occurs by the gas of a gas generator.